Can Religious Belief Be Tested?

In response to:

In his generous, fair-minded review of Alvin Plantinga’s Where the Conflict Really Lies: Science, Religion, and Naturalism [“A Philosopher Defends Religion,” NYR, September 27], Thomas Nagel finds that “it is of great interest to be presented with a lucid and sophisticated account of how someone who holds [Calvinistic] beliefs understands them to harmonize with and indeed to provide crucial support for the methods and results of the natural sciences.”

I fear he fails however to notice a very simple inadequacy in Plantinga’s account, viz., its commitment not so much to theological views as to substantive psychological ones, for which, however, he produces not a shred of serious evidence. As Nagel notes, Plantinga claims that “God endows human beings with a sensus divinitatis that ordinarily leads them to believe in him…[which] in atheists…is either blocked or not functioning properly.”

Perhaps. Animals certainly can have surprising sense modalities. To take one of Nagel’s own favorite examples, bats have been endowed with an echolocation sense, enabling them to sense objects by sonar. Perhaps people are endowed not only with an ability to sense God, but also to read the minds of others, communicate with the dead, and directly foresee the future. Many people and some religions have claimed the latter. The claims have not, however, withstood scrutiny. What evidence is there to believe that we do in fact have a sensus divinitatis? Appeals to believers such as Aquinas and Calvin are obviously not sufficient. One needs independent evidence (indeed, surely double-blind experiments). Until even a modicum of serious evidence is produced for the hypothesis, it remains difficult to see why Plantinga’s—again, psychological—claim is of any more interest than the similar claims of telepaths and the like.

Georges Rey
Professor of Philosophy
University of Maryland
College Park, Maryland

Thomas Nagel replies:

Like Georges Rey, I look at religious belief from the outside, and naturally feel the pull of his insistence that it be tested by independent standards. But Plantinga addresses this demand in detail, and makes a serious case that it is question-begging.

Plantinga observes that the vast majority of people, even today, find it natural to believe in God. That is a psychological claim that can be confirmed or disconfirmed by empirical evidence. But the further claim that this belief is the product of a sensus divinitatis implanted in us by God is not, in Plantinga’s view, provable either empirically or by other means. Rather, it is a theological hypothesis which, if true, would make this kind of basic belief a form of knowledge. If God does not exist, then of course the belief, however natural, is false; Plantinga’s book discusses alternative explanations of it, such as those offered by Freud and by certain evolutionary psychologists.

But Plantinga’s central claim is that if the belief is true, it cannot be confirmed in a noncircular way—any more than the belief that we perceive an external physical world or the belief that we remember a real past. He contends that to require that the belief in God be confirmed by independent evidence is to hold it to a standard that cannot be met by other basic forms of belief, since the warrant for all of them depends on hypotheses about their causes that cannot be proved. That perception gives us knowledge of an external physical world is, in a sense, a “substantive psychological” claim, but it can’t be tested by independent evidence, even with the help of double-blind experiments, and neither, according to Plantinga, can belief in God.

The result is a standoff: whether atheists or theists are right depends on facts about reality that neither of them can prove.